US 12,313,102 B2
Hydraulic pump performance deterioration detection system
Akihiro Kondo, Kobe (JP); and Hiroaki Mitsui, Kobe (JP)
Assigned to KAWASAKI JUKOGYO KABUSHIKI KAISHA, Kobe (JP)
Filed by KAWASAKI JUKOGYO KABUSHIKI KAISHA, Kobe (JP)
Filed on Oct. 18, 2023, as Appl. No. 18/381,500.
Claims priority of application No. 2022-174247 (JP), filed on Oct. 31, 2022.
Prior Publication US 2024/0141885 A1, May 2, 2024
Int. Cl. F15B 21/08 (2006.01); F15B 19/00 (2006.01); F15B 20/00 (2006.01)
CPC F15B 21/08 (2013.01) [F15B 19/005 (2013.01); F15B 20/004 (2013.01); F15B 2211/45 (2013.01); F15B 2211/6309 (2013.01); F15B 2211/633 (2013.01); F15B 2211/6651 (2013.01); F15B 2211/6652 (2013.01); F15B 2211/8633 (2013.01); F15B 2211/87 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A hydraulic pump performance deterioration detection system comprising:
a variable displacement hydraulic pump;
a switching valve that is connected to the hydraulic pump by a pump line, connected to a tank by a tank line, and connected to a hydraulic actuator by a pair of supply/discharge lines, wherein placing the switching valve in a neutral position in which the switching valve blocks the pump line causes the hydraulic actuator to not move, and the switching valve is switched from the neutral position to a first acting position in which the switching valve causes the hydraulic actuator to move in a first direction, or to a second acting position in which the switching valve causes the hydraulic actuator to move in a second direction;
a regulator that changes a displacement of the hydraulic pump in accordance with a command current and that limits the displacement of the hydraulic pump to a limiting value when a delivery pressure of the hydraulic pump has become higher than a setting value;
control circuitry that feeds the command current to the regulator, the control circuitry including a hardware processor; and
a pressure sensor that measures the delivery pressure of the hydraulic pump,
wherein with the hydraulic actuator not moving the control circuitry:
feeds the command current to the regulator such that the displacement of the hydraulic pump is minimized, and
performs a performance check to determine whether or not performance of the hydraulic pump has deteriorated based on a current value of the command current and the delivery pressure of the hydraulic pump measured by the pressure sensor.